On Thu, 27 Dec 2012, Riccardo (Jack) Lucchetti wrote:
On Wed, 26 Dec 2012, Clive Nicholas wrote:
> Hello all!
>
> I've just joined the list and I'm a brand new user of -gretl-. I've only
> been using it for three days and I must praise the team for delivering a
> highly usable, flexible and interactive package that runs pretty much all
> of the econometric models that I want to fit (and a big, fat users' guide,
> too!) - and for free. Can't say fairer than that.
Glad you like gretl. Welcome to the community!
> I do have one query, however. Following Allison (2009), I'm seeking to
> implement his alternative to the Hausman test after fitting a random
> effects panel model, which he argues has "probably better statistical
> properties" than Hausman.
[...]
> Everything goes to plan until I try to implement step (f). Clicking on the
> Tests tab and then selecting Lingg ear Restrictions, I typed:
>
> b[m_n] = b[d_n]
>
> but I receive a "parse error in 'b[m_n] = b[d_n]'" error message.
Deleting
> the spaces either side of the = made no difference. I only got results by
> running:
>
> Restriction set
> 1: b[m_n] - b[d_n] = 0
> 2: b[m_k] - b[d_k] = 0
> 3: b[m_ys] - b[d_ys] = 0
When you write restrictions for the "restrict" command, no coefficients must
appear on the right-hand side of the equality. This is stated in the
documentation.
> Test statistic: F(3, 1016) = 3.27298, with p-value = 0.0205637
>
> This test would appear to comprehensively reject the RE model in favour of
> retaining the FE model. Or does it? Is this an acceptable test in place of
> the Wald test for jointly equal parameters that I can't run in -gretl-?
I'd just add to Jack's reply: this _is_ a Wald test for
jointly equal parameters (the F-form of the test). If you
multiply the test statistic by 3 and refer it to the
chi-square(3) distribution you get the same p-value as given
above.
Allin Cottrell